Took my 90 Roadster out for a spin yesterday. Seems like it's running rich. Sorta an egg/sulfa smell. Had it tuned up last year with only 5,000 miles put on it since. Any idea what direction I should start with?

 

posb 02 sensor

 

The other thing I'd check is the catalytic converter. I have smelt some very ripe ones before that were toast... just an idea.

 

My gas went sour after sitting up 4 months!
Premiun might have been old when I bought it.
Ran rich black smoked choked down and check engine light came on after idleing a minute.
After burning out bad gas and putting in fresh plus some Lucas additive it runs normal again.
Close call I'd say.

 

Mech what do you suggest? replace the o2 sensor first????

 

Well you could, but I would check and see what kind voltage readings you are getting. If it stays closer to 1 volt d/c, it is a rich condition. But it may not necessarily be the o2. While idleing, pull your vacuum line off the brake booster and watch the voltage. If the O2 is working properly, it will drop almost immediately to about .1 or .2 volts. A good O2 will be cycleing rich to lean quite actively on a warmed up properly tuned engine. Check your TPS signal voltage and your coolant temp voltage. TPS around 1/2 volt @ idle, coolant temp sensor should be around 1 volt warmed up (I think), not sure on the CTS without my manual to look at. [8D]

 

Mech259, brought my vette to my local mechanic today. First, on the way the brakes got squishy. They said the master cylinder was gone. Guess the timing was right to have that fixed. Anyways, the sulfa smell. At this time they are saying either the fuel presser regulator (adjustable) is gone or the one of the injectors is gone leaking fuel causing it to dump fuel making it run rich. Sound right to you? Thanks.

 

That is possible. You can pull spark plugs to see if it is. If they are blacked up or coked, then it is running rich. Also watching your O2 voltage likeI described earlier will tell you. Good Luck.

 

Just an update on this post. The mechanic said that my injectors were loosing pressure after the car was shut off. He checked the pressure regulator (adjustable) an it had crap in it as well as the injectors. The fuel line had to be blown out and the fuel filter changed. Then he finds the fuel pump to be shot. Now the mechanic finds metal shaving in the fuel tank. WTF.... He tried to get as much out as possible and showed me what he took out. His thoughts were that when the fuel pump failed it caused the metal shavings in the tank? Anyone ever hear of this. Tried to save me from the cost of dropping and flushing the tank. Anyways I drove it doing some errands (cheap excuse for a ride) and it drove well. The next day I take it out for some more errands and at stop lights when I step on the gas to go it bucks like I'm not getting fuel. When I baby it up to speed it seems to go fine. My thoughts are another fuel filter change and maybe time to drop the tank. This is really starting to suck. Oh by the way the injectors were changed as well as the pressure regulator. All to the tune of $1500.

 

Well, if you had metal in the tank, then get ready to change the fuel filter a few more times until it cleans it up because it will stop up the fuel filter in a hurry.